built a Moxon antenna but it is not resonant at the
design frequency, or the gain seems low, or the front-to-back
ratio is disappointing. You wonder what to do to improve
have plans to build a Moxon antenna. You have combed
through everything in the MoxonAntennaProject so how
to build it is clearly in mind. You have the MoxGen
program so you have the necessary dimensions. However,
you have your own ideas for construction. You
wonder what will happen to tuning or performance if?
pondered these problems and came up with an excellent
solution using the 4NEC2 optimizer functions. Dick
As for hams in general I have been in constant awe of the brilliant and
ingenious people in the field. My thoughts about modelers and
optimization is probably from forums where the topic is rarely seen and
when seen, commonly at the discovery level.
Having looked at a number of Moxon dimension sets found on the
internet, almost all can model at a workable range under 1.8 SWR and
usually under 1.5. The Moxon configuration is quite tolerant of
variation. Those using MoxGen dimensions consistently report values
mid-way between broad tuning, gain and front-to-back ratio. Depending
on a hams interests or problems, the optimization function can show the
provides a PDF document.
Here is something you will be interested in.
Using the meander principle and optimization of the width and height of
the meanders, I got some interesting results for same height and wire
size at 28.4 MHz.
Moxon: A=12.6 ft, B=1.87 ft, D=2.33 ft, E= 4.67ft, Gain=9.81 & -18 dBi
Meander: A=6.48 ft, B=1.86 ft, D=2.21 ft, E=5.16 ft, Gain=9.07 & -4.2 dBi
It is about half as wide and about 6 inches more on the sides.
Gain goes down about 1 dBi and Back rejection goes down a lot.
I will let you know how the prototype turns out. --73, Dick, KK4OBI